Visual qualities:
Similarly to narrow products, bent products are manufactured on the market in two different versions.

Surface processing does not affect the load-bearing capacity or the strength class of a finished product.

Visible quality:
a visible constructional element, for example in residential premises or in rooms serving for social purposes (sporting halls, churches, chapels, kindergartens)

Industrial quality:
an invisible constructional element

Surface treatment:
all four sides are planed smooth

Sharp edge working:
all edges are rounded or cut off at 45°

impregnation-free, impregnated, glazed

one-off impregnation, protection against pests and putrefaction. By soaking or coating.

Varnishing, glazing:
the option to use various colour types recommended by the producer. No less than two layers. Each layer needs at least 24 hours for hardening, drying.

Quality criteria Visible quality Industrial quality
Planed quality Planed smooth or grinded-off
Surface roughness up to 1 mm
Elimination of roughness
Greater roughness is permitted too
Knots Fixed are permitted
Knot holes are permitted up to the diameter from 0 to 20 mm or close to the 20 mm diameter
Fixed are permitted
Knot holes are permitted
Resin pockets Permitted up to 5 x 50 mm Permitted
Pith Permitted Permitted
Insect infestation Permitted holes up to 2 mm Permitted holes up to 2 mm
Discolorations Blue and red stripes are permitted up to max. 5% of the whole surface Blue and red stripes are permitted
Shrinkage cracks Permitted up to the thickness of 4 mm No limitation